It is common to pack multiple containers such as cans or bottles into individual cases for shipment, storage or the like in varying configurations. Prior machines used for packing a plurality of cans, for example, into individual cases have, or face, a number of inherent problems. Such packing machines are generally used in large volume operations where thousands of cans must be conveyed, metered, separated, grouped and inserted into cases in the proper count orientation and at the high speeds demanded by producers. The cans are mass-fed and pressures of the mass-feed system and metering or counting stations must be handled without can damage and without adverse affect on the can handling systems downstream. Such pressures or the use of separating wedges and the like may unduly force cans into any can metering system, making the cans hard to separate, or may damage the cans. These pressures, in conjunction with can metering systems, may thus cause undesirable pulsations in the system, and can damage.
Another major problem in such systems is the tolerance of the system to emergency stops which can occur for numerous reasons, such as can damage, absence of a properly erected carton or case, downstream stoppage, jams and the like.
Still other significant problems arise in such systems in connection with start-up, carton run-out and full run-out modes of operation. When the systems are started, it is difficult to fully "prime" the system to fully fill the first cartons, thus initially producing a number of partially-filled cartons which cannot be sealed and shipped. Also, it is difficult to insure that all cartons at the end of the run will be filled. Finally, when it is desired to use up all cartons and cans in the system, it is difficult to end up with the last carton fully filled and no further cans in the intermediate metering or transfer system. In other words, it is difficult to prevent incomplete loads in the metering system on full run-out, with no empty cartons in the transport system.
Many of these difficulties are, of course, traceable back to the need to separate rows of cans into predetermined rows of select count groups for combination with other rows for proper grouping in a carton or case.
It is thus desirable, and one objective of the invention is, to provide an improved case packer capable of separating an intermediate metering function from the pressure of an infeeding mass of cans.
Another objective of the invention is, in a case packer, to minimize pressure on the cans when grouping is performed.
Another objective of the invention is to provide a case packer with no pulsation of cans in the feed or grouping areas.
A further objective of the invention has been to provide an improved case packer which is tolerant of emergency stops.
Another objective of the invention is to provide an improved case packer capable of fully loading the first case presented upon packer start-up.
Another objective of the invention has been to provide an improved case packer capable of fully filling a last carton to be filled without clearing the upstream infeed mass of cans, and without leaving cans in the metering stage of the packer.
A yet further objective of the invention has been to provide an improved case packer capable of accommodating a full case and can run-out so no cans will be left in the transfer and so no empty case will be left unfilled or partially filled.
In another aspect of the invention, it is desirable to introduce cans into cases or cartons in a particular pattern and thus to control the pattern so that no undesirable voids or spaces are left in the carton. Particularly, if the cans are not maintained in predetermined rows, properly oriented with respect to each other, the cans bridge or roll into a nestled, so-called "A" pattern lock-up configuration which will not permit all cans to be inserted into the case and it cannot be closed. Such occurs when three or four cans in one row, for example, nestle into the spaces between cans in an adjacent row so as to be staggered, with the row-ends out of alignment. This upsets the desired packing configuration as noted.
In the past, case loaders such as barrel loaders have been used to push a row, or a group of confined rows, directly into an open carton. The barrel loaders comprise a series of pushers conveyed in the direction of cartons being loaded but transversely selectively extensible to push a group of cans into cases. While this works, the extensive mechanisms, complexity, space requirements and cost of a barrel loader make it desirable to provide an improved loader.
One such different device is a rotary loader looking much like a gear wheel. A plurality of extensions are circumferentially spaced about a hub. The extension spacing and hub speed are correlated with cases to be loaded so the extensions rotate respectively into a position for pushing a group of cans into a respective open case moving in a straight line past the loader. The difficulty with such a device is that the can-pushing face of the extension is not parallel to the case mouth except at the instance when the case moves through a radial extending from the hub axis through the center of the hub extension. Thus the extension face engages the cans on an angle and other than parallel to the case mouth. This can allow cans to move out of a line parallel to the case mouth and cans might bridge or move into an undesirable "A" pattern lock-up type configuration where the rows of cans thereafter cannot be loaded fully into a case.
Accordingly, it has been a further objective of the invention to provide an improved loader for a case packer and which prevents cans in a row to be loaded from shifting along or out of the rows and causing an undesirable bridge or can lockup, preventing full loading of cans.